1. Field of the Invention
The invention regards a distance measuring device, in particular, a magnetostrictive distance measuring device.
The basic principle is that a distance measuring element extends in longitudinal direction of the device along the measurable measuring distance with a signal generating position sensor moveable relative to it in longitudinal direction.
In a magnetostrictive distance measuring device, the basic principle of such a device is refined so that a wave conductor made from a material that is electrically conductive, and can also be magnetized in measuring direction, extends in the longitudinal direction of the device, in particular, in a slightly taunt state.
A magnet is connected to the component, whose position in longitudinal direction is to be measured or surveyed, and is moved through this component in longitudinal direction along the wave conductor without touching it but with a sufficiently small distance.
An electrical impulse entered into the wave conductor causes a mechanical wave in response to the magnet, which propagates from the position of the magnet along the wave conductor and which is detected by the processing electronics mostly located at the end of the wave conductor, with respect to its travel time, from which the longitudinal position of the magnet and thereby of the component to be surveyed relative to the wave conductor is known.
Since such distance measuring devices are often used in machines, also in manufacturing machines, they have to comply with a group of requirements, e.g. protection of the measuring device against mechanical impact and contamination, in particular, against penetration of moisture into the processing electronics, maintenance of the initial tension of the wave conductor, shielding of the electromagnetic radiation of the processing electronics to the outside and to the inside, ease of mounting and maintenance of the measuring device.
On the one hand, it is state of the art to receive the wave conductor in a supporting but not too strongly dampening enclosure and handling the wave conductor unit this way.
On the other hand, it is state of the art to locate the wave conductor or the above mentioned wave conductor unit protected in the interior of a circumferentially enclosed, hollow tubular profile, which can be economically produced as an extruded profile.
Thereby the tubular profiles, depending on the application, have to fulfill different requirements, such as:                high stiffness against bending loads in lateral direction;        low space requirement, especially as a very flat tubular profile;        symmetric shape of the interior of the tube for various applications;        specific mounting of the tubular profile relative to the base;        Rotability of the tubular cross section, in particular also in already mounted state, relative to the component carrying the profile;        particularly economic manufacture; and        Capability of locating it in an additional, protective second housing.        